US 2007/0147579 A1 discloses a computed tomography apparatus comprising an X-ray source for generating X-rays which traverse an imaging region. The computed tomography apparatus further comprises a detector for generating detection values depending on the X-rays after having traversed the imaging region. The X-ray source is rotated around the imaging region for allowing the X-rays to traverse the imaging region in different directions. The intensity of the X-rays is modulated as a function of time such that sensitive organs like eyes of a person are irradiated with a minimum dose required to provide an image with a desired noise variance. This reduces the overall dose applied to a person and, in particular, the dose applied to sensitive organs.
However, the varying intensity of the X-rays as function of time leads to image artifacts, thereby decreasing the quality of the reconstructed images.